The present invention relates to a method for providing efficient uniform delivery of a predetermined amount of water needed for a specific crop planted on sloping land.
There have been a wide variety of irrigation systems in the past, such as underground irrigation systems having an underground pipe having sprinklers attached for irrigating a surrounding field or grove and drip irrigation systems. Center pivot irrigation systems are also commonly used today in the irrigation of large fields and these typically comprise a long water conduit which is pivotably connected at one end to a source of water under pressure. The conduit arm is carried in an elevated position by a plurality of spaced wheels or wheeled towers which are powered by hydraulic, pneumatic, or electric motors to rotatably sweep the central conduit over a circular pattern in a field. Center pivot and similar irrigation systems are not well adapted for sloping land since the wheeled towers that the system rides on cannot readily traverse unequal terrain.
Standard irrigation systems which layout irrigation pipes for distributing water through sprinklers, drip, ditches or other methods are also not well suited to sloping terrain because sloping pipes produce varying amounts of water pressure throughout the pipes and thus produces a wide variation in the amount of water distributed at any one point in the pipe. This can result in flooding and erosion of the soil when too much water is dispensed or there is an uneven distribution of water. If an irrigation hose extending down a slope is continuously filled with water, the pressure will increase at the bottom depending upon the amount of the drop. On the other hand, in continuously flowing water, the friction of the water running through the pipe tends to reduce the water pressure.
The present invention is designed to provide an efficient uniform delivery of a predetermined amount of water needed for a specific crop planted on sloping land that will not cause erosion or flooding and will provide an even distribution of water over the entire crop. This is accomplished by selecting a fertile piece of sloping land which has access to a water source, such as a stream, river, reservoir, or well, and obtaining a detailed topographical map and field survey of the field to be planted. From this map the length of the longest seed bed is determined and the maximum amount of water which must be delivered to that seed bed is calculated based on the number of plants and the irrigation requirements of the selected crop to be planted.
Using this maximum amount of water which must be carried by an irrigation hose, the required hose size can be determined. First, the hose pressure for the entire system is selected. Low pressure facilitates setting the header valve which controls the amount of water put into each irrigation hose and also leads to certain economies. Selecting, as an example, a pressure of one foot of head of water, less than one half pound per square inch, a one quarter inch diameter orifice will pass about three quarters of a gallon per minute, enough for about a 3000 foot long seedbed. Therefore, one quarter inch diameter hose is ample for this example.
The irrigation hoses are laid out gently crossing the contours of the slope to maintain a generally constant downward gradient to increase pressure to counteract the loss of pressure due to friction of the water running through the hose and to maintain the selected head of water pressure throughout the length of the hose. The reduction in water pressure due to friction is also dependent upon the finish of the interior surface of a particular hose as well as the interior diameter.
Prior art U.S. patents may be seen in the Fowler et al. U.S. Pat. No. 6,512,992 for an irrigation positioning system which includes a means of accurately determining the position of a selected location, such as at the end of a center pivot irrigation system by using two global positioning system (GPS) receivers. The Hauwiller et al. U.S. Pat. No. 6,606,542 provides for a system and method for creating agricultural decisions and application maps for automated agricultural machines. A system for creating application maps for controlling a dispensing apparatus based upon field data includes a system for maintaining the field data. The field data may be geo-referenced relative to geographic coordinates of the location of the field data. Application rate equations for correlating field data relative to desired output may be selectively defined based upon selected field data and desired output to produce application maps for a particular field.
The Carrozza U.S. Pat. No. 5,040,729 provides a sprinkler system which employs an articulated riser for adjustable sprinkler head positioning on an underground sprinkling system to compensate for ground irregularities by adjusting the position of the riser. The Huntley U.S. Pat. No. 6,308,902 is for a drip irrigation hose with emitters having different discharge rates. The hose has a water supply passage and a plurality of flow regulating channels manufactured into the hose that are smaller than the water supply passage. The flow regulating channels each comprise a predesignated geometry to provide a desired discharge rate at a given pressure and an inlet section comprising one or more openings connecting the water supply passage to that flow regulating channel and an outlet section comprising openings connecting that flow regulating channel to the exterior of the hose. The flow regulating channels have at least two different geometries to provide at least two different discharge rates at the given pressure.
The DeFrank U.S. Pat. No. 5,458,712 is a process for forming drip irrigation hose with pressure compensation. The Rawlins U.S. Pat. No. 5,845,229 is a method and apparatus for mapping crop quality. A harvester has a global positioning system that is used in the harvesting of crops. Fields to be harvested are divided into individual field areas for crop quality and values representing the location of the selected individual field areas or crop management areas are loaded into storage on a computer. The Atkinson et al. U.S. Pat. No. 6,236,938 is a system and method for creating maps using a GPS system. The system includes a computing device, a global positioning system receiver in communication with the computing device, and a range finder in communication with the computing device. The GPS receiver obtains a positioning location while a range finder is used to locate distances. The Keller et al. U.S. Pat. No. 6,553,299 is a method and apparatus for precision agriculture operations utilizing real time kinematic global positioning systems. Real time kinematic global positioning system technology is integrated with precision farming methodologies to provide accurate seeding, cultivating, planting and/or harvesting operations. The systems are used to control fully or semi-autonomous vehicles in the operation of the farm which allow for precision planting of seeds, precision weed removal as well as crop fertilization.
In contrast to the prior art, the present invention is directed towards a method of irrigating sloping land with an irrigation system laid out based on a topographical map to maintain a constant pressure head throughout the length of the hose by having the downward gradient at every point along the hose increase the pressure to offset the loss of pressure due to friction of the amount of water flowing through the hose at that point. This maintains a uniform pressure in the pipe to give an efficient uniform delivery of a predetermined amount of water needed for a specific crop planted on the sloping land which will not cause flooding or soil erosion and will allow the previously unused sloping land to be planted with a crop.